Wikijunior:Human Body/ExcretorySystem

The excretory system is how our bodies get rid of things they don't need. This is called waste. The urinary system is a part of this, but there are also other organs that help our bodies get rid of waste.

The largest organs in the excretory system are the kidneys. There are 2 of them. They are shaped like large reddish brown beans. They are about the size of a fist and are located on each side of your back.

Running from the kidneys to the bladder are two long skinny tubes called ureters.

The bladder is a hollow organ that holds urine. It can stretch to hold more liquid. There is another tube called the urethra that carries urine out of the body.

There are several parts of the excretory system. To get rid of liquid waste in our bodies, we have two kidneys, two ureters, a bladder, and a urethra.

Kidneys filter our blood to get rid of things if our blood that are not needed. If we didn’t have kidneys, we would eventually be poisoned by this waste. The kidneys are full of millions of microscopic things called nephrons. They filter the blood and produce urine. Urine is the liquid that leaves your body when you go to the bathroom.

The urine travels down two tubes called ureters to get to the bladder. The bladder is where urine is stored until you go to the bathroom. The last tube the urine goes through to leave the body is called the urethra.

Solid wastes leave the body through the rectum, as described in the section on the digestive system. The lungs are also a part of the excretory system. They get rid of the carbon dioxide that our bodies don’t need. This happens when we breathe out, as is described in the section on the respiratory system.

One other part of the excretory system is our sweat glands. The purpose of sweat glands is to keep our bodies cool and also to get rid of wastes, including salts that our body doesn’t need. Sweat glands are in your skin, and there are over 2 million of them in each person!